The present invention relates generally to camera systems, and more particularly, to a camera system having alignment mechanisms enabling it to image a field of view.
Cameras can be used to collect data in a wide variety of applications. For example, a highway toll station can include one or more cameras for obtaining certain vehicle data, such as license plate information from automobiles passing through the toll area. The captured license plate data is submitted to a pattern recognition system for ultimate collection of toll revenue from the vehicle owner. The cameras used in such a system should be sufficiently rugged to withstand harsh environmental conditions and should be impervious to vibration levels generated by cars and trucks passing through the toll station. In addition, the camera should be relatively easy to align with a desired field of view to capture the license plate data.
In general, such cameras are secured to a bracket that has a fixed position on the toll road. The cameras however, must be properly aligned with the highway so as to image the field of view corresponding to a vehicle license plate. Each time the camera is removed from the housing for servicing it must be re-aligned upon its return. Such re-alignment can be a time-consuming process. Since the camera is unable to process license plate data during the time it is offline, toll revenue collection can be significantly reduced.
It would, therefore, be desirable to provide a camera module that can be rapidly aligned with a predetermined field of view.
The present invention provides a camera system having a camera module for imaging a field a view. The camera module includes a casing and a camera that is collimated with respect to a longitudinal axis of the module. The collimated camera module can be rapidly secured to a mounting bracket, which has a fixed position, such that the camera, upon mounting, is aligned with a predetermined field of view. While the invention is primarily shown and described in conjunction with a highway toll collection system, it will be appreciated that the invention is applicable to other camera systems requiring alignment with a fixed field of view.
In one aspect of the invention, a camera module includes a casing and a camera. The casing that encloses the camera comprises a faceplate that is securable to a mounting bracket for securing the module in a fixed position. A mounting rail extends from the faceplate, which closes one end of the casing. A base plate is movably coupled to the mounting rail such that the base plate is positionable about pitch and yaw axes. The module further includes a camera positioning mechanism for aligning the camera""s optical axis with the longitudinal axis of the module housing by adjusting the position of the base plate in relation to the fixed mounting rail and faceplate.
In one embodiment, the camera positioning mechanism includes a pitch adjustment member, such as a screw, that can be rotated to move the base plate and camera with respect to the mounting rail and thereby determine the pitch position of the camera. Left and right pitch/yaw adjustment members can be rotated to move the base plate in relation to the mounting rail and thereby determine the pitch and yaw position of the camera.
In a further aspect of the invention, a camera module includes a camera having an optical axis that is aligned with a longitudinal axis of the camera module. The camera module is readily matable to a mounting bracket, which in the case of being mounted on a toll road, has a known position on the toll road in relation to a predetermined field of view to be imaged by the camera. A faceplate of the camera module is secured to the mounting bracket such that the camera is aligned with the predetermined field of view upon mounting to the mounting bracket.